Diabetic cardiomyopathy

Diabetes mellitus is associated with a specific cardiomyopathy. This is evident from the clinical-pathological work and the epidemiologic data from the Framingham study. Noninvasive studies of diabetics have shown alterations in systolic and diastolic function that may ultimately lead to clinical heart failure. The relationship of these cardiac changes to the type of diabetes, its duration, and its severity is not settled. However, a correlation between changes in heart function and other complications of diabetes has been demonstrated. Insufficient prospective data is available from noninvasive studies to establish the frequency of progression from subclinical cardiac dysfunction to overt congestive failure. The pathogenesis of this disorder is still uncertain. Pathological studies have shown changes in the intramural arteries, arterioles, and capillaries but their functional significance is uncertain. Experimental studies have shown interstitial changes leading to an apparently less compliant left ventricle in the diabetic dog and monkey. In the diabetic rat reversible changes were found in myocardial function, related to changes in contractile proteins and intracellular calcium metabolism. In both species, the response to anoxia or ischemia was altered in the presence of diabetes. However, irreversible depression of the contractile element was not found in most animal studies of isolated diabetes. In contrast, the combination of hypertension and diabetes leads to substantial cardiac damage and circulatory congestion, both in clinical and experimental investigations. Clearly much more work must be carried out to understand the pathogenesis, treatment, and ultimately the prevention of diabetic cardiomyopathy.     

Effects of tachycardia with normal and ectopic ventricular activation on S-T segment potential and patterns in the dog

Tachycardia induced by atrial pacing in the dog increases the intensity of potentials recorded on the body surface during the ST-T interval. The effects of tachycardia caused by ectopic right or left ventricular stimulation on ventricular recovery potentials were studied in 30 dogs. Rate was increased in a stopwise manner from 90 to 250 beats per minute by atrial pacing (ten dogs), or by left atrial-right ventricular sequential pacing (ten dogs), or by left atrial-left ventricular sequential pacing (ten dogs). ECG effects were determined by construction of body surface isopotential maps from voltages registered from 84 torso electrodes using a P-R segment baseline. Ectopic stimulation intensified the repolarization maximum and shifted its location to correspond with sites of epicardial stimulation. These findings reflect a reduced cancellation of transventricular differences in recovery times, with earliest recovery occurring at earliest activated sites. Increasing rate with any one activation pattern linearly increased potential extrema magnitudes without further changes of spatial features. This singular response to tachycardia regardless of activation sequence is consistent with an increase in the apparent moment of a repolarization dipole without alteration of its orientation.     

Effects of pregnancy, postpartum lactation, and oral contraceptive use on the lipoprotein cholesterol/triglyceride ratio

Lipoprotein cholesterol/triglyceride ratio changes have been observed previously with sex hormone use. To determine if the lipoprotein cholesterol/triglyceride ratio is similarly changed by pregnancy and postpartum lactation, we examined pregnant subjects at 36 weeks gestation and the same women at 6 weeks postpartum and compared them to age-matched, nonpregnant women using or not using oral contraceptives. The cholesterol/triglyceride ratios were examined as means and medians and as curvilinear functions of increasing triglyceride concentration. Median ratios did not predict all ratio changes identified graphically. At very-low-density lipoprotein (VLDL) triglyceride concentrations below 40 mg/dL, the VLDL ratio is less than control in oral contraceptive users and further reduced in pregnant women. Above triglyceride concentrations of 40-60 mg/dL, the curves in the three groups are indistinguishable. No effect of lactation is observed. The low-density lipoprotein (LDL) cholesterol/triglyceride ratio is comparably lower in pregnant subjects and oral contraceptive users at all concentrations of lipoprotein triglyceride and again there is no effect of lactation. In high-density lipoprotein (HDL), there is no effect of either pregnancy or oral contraceptive use on the cholesterol/triglyceride ratio, while it is significantly higher with lactation. Postpartum decreases in the VLDL and LDL cholesterol/triglyceride ratio are seen at all lipoprotein concentrations independent of lactation. We conclude that triglyceride enriches VLDL at low concentrations and LDL at all concentrations in pregnancy and with oral contraceptive use, suggesting a common, hormonal mechanism. HDL is enriched with cholesterol during postpartum lactation, consistent with decreased transfer of cholesterol to other lipoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)     

Smooth muscle contraction bands in the media of coronary arteries: A postmortem marker of antemortem coronary spasm?

To date, no unequivocal morphologic markers have been described that would allow the diagnosis of coronary artery spasm to be made at autopsy. The coronary arteries of 63 adult patients without myocardial infarction were examined at autopsy, and the presence of medial smooth muscle contraction bands in these vessels was correlated with other vascular changes, myocardial pathologic changes and clinical history. These contraction bands have not been reported previously in human coronary arteries, but they were identified in experimental vascular spasm induced with catecholamines. It was found that 47 of the 63 cases were positive for contraction bands. As evidence of an antemortem process, there was a significant correlation between these changes and the presence of nonocclusive microthrombi, found in 25 cases. Contraction bands were also highly correlated with atherosclerotic plaque ruptures and mural plaque hemorrhages, which may be secondary to coronary spasm. In 78.7% of the cases positive for contraction bands, the cause of death was related to a diagnosis possibly associated with high catecholamine levels. On the basis of experimental evidence and the correlations identified in this study, coronary artery medial smooth muscle contraction bands may represent a postmortem marker of antemortem coronary spasm.     

Prorating WAIS – IV summary scores for patients with relapsing-remitting multiple sclerosis

We evaluated the utility of prorating appropriate combinations of two, six and eight Wechsler Adult Intelligence Scale – Fourth Edition (WAIS – IV) subtests for estimating the Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Full Scale IQ (FSIQ) and General Ability Index (GAI) in a sample of individuals diagnosed with multiple sclerosis (MS). Forty-eight outpatients completed the WAIS – IV and Wechsler Memory Scale – Fourth Edition (WMS – IV) as part of a comprehensive neuropsychological battery. Means for age, education and duration of diagnosis were 42.35, 14.21 and 8.30 years, respectively. Paired t-tests showed no significant differences between prorated and standard means for VCI (93.46 vs. 93.73), PRI (90.19 vs. 89.44), FSIQ (88.53 vs. 88.47) or GAI (90.56 vs. 90.65). Correlations between prorated and standard composites were ≥0.89 in every instance. Correlations between the standard and prorated composites and education, disability status and WMS – IV indexes did not reveal a single contrast, where the correlations were significantly different. The present findings support the use of the two-subtest VCI and PRI composites and the eight-subtest FSIQ and four-subtest GAI in the assessment of patients with MS.     

精索静脉曲张严重少精子症患者Y染色体微缺失分析

目的:探讨精索静脉曲张和Y染色体微缺失对生精障碍的影响。方法:对随机挑选的100例左侧精索静脉曲张严重少精子症患者(精子浓度<5×106/ml,组1),100例左侧精索静脉曲张轻度少精子症患者[精子浓度(10～20)×106/ml,组2],100例特发性严重少精子症患者(组3),100例特发性轻度少精子症患者(组4)和30例正常生育男性对照组(组5)采用聚合酶链反应(PCR)技术进行Y染色体微缺失检测,选取无精子因子(AZF)a、b和c区9个序列标签位点(STS)。结果:组1中有19例患者存在AZF微缺失(19%);组3中有11例患者存在AZF微缺失(11%),其余各组均未发现AZF微缺失;组1比组3有较高的缺失率。结论:在治疗精索静脉曲张严重生精障碍患者前应先进行Y染色体微缺失检测,避免不必要的治疗。     

两种不同钢板内固定治疗跟骨关节内骨折的效果比较

[目的]比较"Y"形钢板和解剖型钢板内固定治疗跟骨关节内骨折的疗效。[方法]将本院2009年1月～2010年1月收治的84例(88足)跟骨关节内骨折患者随机分为"Y"形钢板内固定治疗组(简称"Y"形组)和解剖型钢板内固定治疗组(简称解剖型组);回顾分析两组的围术期指标(手术时间、术中出血量、切口长度、住院时间),手术前后放射学指标(跟骨情况、Bhler角、Gissane角、距下关节面的移位),术后恢复情况(Maryland评分、距下关节活动度),并发症情况。[结果](1)两组在围术期指标和并发症上没有差异(P>0.05);(2)两组术后的放射学指标均优于术前且有统计学差异,解剖型组的跟骨高度(P<0.05),Bhler角(P<0.01)、Gissane角(P<0.01)大于"Y"形组,距下关节面的移位小于"Y"形组(P<0.05);(3)解剖型组术后1年的Maryland评分高于"Y"形组(P<0.05),且累积优良率高于"Y"形组(P<0.01),术后1年的轻度和显著受限情况均优于"Y"形组(P<0.01)。[结论]解剖型钢板内固定治疗跟骨关节内骨折的效果较好。     

V-Y肌腱瓣修补术治疗陈旧性跟腱断裂

目的 研究V—Y肌腱瓣修补术治疗陈旧性跟腱断裂的手术方法及结果。方法 对9例平均112d的陈旧性跟腱断裂患，采用小腿三头肌V—Y肌腱瓣修补术治疗修补缺损为3．2～6cm，平均4．6cm。结果 平均随访2年8个月，按Arner-Lindholm疗效评定标准评估，优7例(77．8％)，良2例(22．2％)，优良率为100％。结论 对于陈旧性跟腱断裂，小腿三头肌V—Y肌腱瓣修补术足一种方法简单、疗效满意的手术方法。     

Multicentre study of Y chromosome microdeletions in 1,808 Chinese infertile males using multiplex and real‐time polymerase chain reaction

Azoospermia factor (AZF) genes on the long arm of the human Y chromosome are involved in spermatogenesis, and microdeletions in the AZF region have been recognised to be the second major genetic cause of spermatogenetic failure resulting in male infertility. While screening for these microdeletions can avoid unnecessary medical and surgical treatments, current methods are generally time‐consuming. Therefore, we established a new method to detect and analyse microdeletions in the AZF region quickly, safely and efficiently. In total, 1,808 patients with spermatogenetic failure were recruited from three hospitals in southern China, of which 600 patients were randomly selected for screening for Y chromosome microdeletions in AZF regions employing real‐time polymerase chain reaction with a TaqMan probe. In our study, of 1,808 infertile patients, 150 (8.3%) were found to bear microdeletions in the Y chromosome using multiplex PCR, while no deletions were found in the controls. Among the AZF deletions detected, two were in AZFa, three in AZFb, 35 in AZFc, three in AZFb+c and two in AZFa+b+c. Our method is fast—it permits the scanning of DNA from a patient in one and a half hours—and reliable, minimising the risk of cross‐contamination and false‐positive and false‐negative results.